It is a known fact that a problem normally arises with both the electrical connection and the mechanical connection in the construction of lamp units for lighting of the industrial and civil type having a fluorescent tube or an incandescent lamp, which consist of an enclosing body or shell (housing) of heat-resistant or self-extinguishing polycarbonate resin incorporating a transparent diffuser.
Generally the known prior art lamps are attached mechanically by drilling holes in the ceiling or wall and inserting expanding plugs into the holes and connecting the lamps to electrical cables previously mounted in the ceiling or wall. All of these operations are time-consuming, laborious and not without disadvantages.
In addition to the difficulties and excessive time required both for mounting and for any maintenance operations which require dismantling there is a risk of damage to the surface finish of plasterwork and paintwork.
Attachment systems are also known wherein a plate or bracket acts both as a mechanical support and as an electrical connections with the supply cables ending in a plug connector attached mechanically to the finished walls. The lamp body may through sliding or by other manipulation become secured by means of a snap-on device and the electrical connection is made at the same time with means provided on both the bracket and the lamp body.
The system consisting of an open box housing which contains the electrical plug connector unit which is secured to the ends of the supply cables in the ceiling or wall and in which the said housing is attached to the surface by means of wall plugs is also known. The supporting frame, the diffuser and the remainder of the lamp are attached to the housing by means of a quick-attachment system incorporating bayonet attachments and the quick electrically connected the the box is offered up and electrically connected. The advantage of this system is its simple and quick attachment and disconnection, on the other hand, there remains the disadvantage that the lighting equipment is not watertight.